RSA是被研究得最广泛的公钥算法，从提出到现在已近二十年，经历了各种攻击的考验，逐渐为人们接受，普遍认为是目前最优秀的公钥方案之一。RSA的安全性依赖于大数的因子分解，但并没有从理论上证明破译RSA的难度与大数分解难度等价。即RSA的重大缺陷是无法从理论上把握它的保密性能如何，而且密码学界多数人士倾向于因子分解不是NPC问题。-RSA is the most widely studied of the public key algorithm, from the nearly two decades now, we have tested a variety of attacks, people gradually accepted, widely considered the best of the current public key, one of the options. The security of RSA relies on the factorization of large numbers, but in theory there is no proof of the difficulty of deciphering the RSA and the decomposition of large numbers equivalent difficulty. RSA' s major flaws that can not grasp it from the theory of how the confidentiality of the performance, but most scholars tended password factorization problem is not a NPC.